Methods and systems have been developed for manufacturing multi-color cosmetic sticks, such as lipsticks, involving inserting two or more different cosmetic materials, such as two or more portions of different colors, into a mold. The following references are incorporated herein by reference in their entireties.
U.S. Pat. No. 4,291,018 discloses a lipstick having a construction of the core-sheath type which comprises two different compositions A and B arranged in core-sheath relationship, the composition A consisting essentially of a homogeneous mixture of from 53 to 85% by weight of a low-viscosity oily ingredient having a viscosity of less than approximately 80 centipoises at 36 degrees Celsius and from 15 to 47% by weight of a waxy ingredient having the form of a solid at 36 degrees Celsius and the composition B consisting essentially of a homogeneous mixture of from 40 to 90% by weight of a viscous oily ingredient having a viscosity of at least 200 centipoises at 36 degrees Celsius and from 10 to 60% by weight of said waxy ingredient. When applied to the lips, this lipstick causes no tacky or disagreeable sensation, spreads well with a soft feel and a light touch, adheres evenly to the lips and gives protection thereto, and provides a good and beautiful gloss, clarity, hue, and color development.
U.S. Pat. No. 7,073,965 discloses a multi-composition stick product, such as a lip balm, sun screen, deodorant, or glue stick. The multi-composition stick product including a stick composition molded in the container so as to contact the walls thereof and be advanceable or ejected therefrom. The stick composition includes a first composition and a second composition. The first and second compositions differ in at least one component, such as a medicament, colorant, fragrance, flavorant, sunscreen, preservative, conditioner, moisturizer, emollient, or surfactant. Furthermore the first and second compositions are arranged in a predetermined non-random pattern that is reproducible. Also described is the method and apparatus for manufacturing the multi-composition stick product.
U.S. Pat. No. 4,743,443 discloses a tri-color or alternating bi-color lipstick and method of molding the same is disclosed. The lipstick is formed using a known book-type mold. The color divisions are achieved by using a removable insert. One insert is used to form the middle section. Another insert is a solid plate and is used to prevent lipstick product from entering the middle section while the outer sections are being filled. In use, the lipstick is axially rotated by the user to present the desired color to the lips. In serial or simultaneous fashion, more than one color may be applied to permit blending.